Hi Walsh, thanks for sharing your experience. I am aware compiling kernels nowadays as probably quite easy, however when it comes to packaging and maintainability together with depend packages it becomes cumbersome. I need this kernel rather for productive systems and would like to have this simplified as best as possible at different ends. So my request is really serious in regards to this special feature in this kernel and I am wondering why this is not available at all? Thanks Thomas On 6/9/21 8:18 AM, L A Walsh wrote:
On 2021/06/07 06:54, Thomas Hartwig wrote:
Hi,
for some reason PREEMPT is configured for 250? Am I missing something or is it by error?
$: grep CONFIG_HZ /boot/config-5.3.18-lp152.75-preempt # CONFIG_HZ_PERIODIC is not set # CONFIG_HZ_100 is not set CONFIG_HZ_250=y # CONFIG_HZ_300 is not set # CONFIG_HZ_1000 is not set CONFIG_HZ=250
# CONFIG_PREEMPT_NONE is not set CONFIG_PREEMPT_VOLUNTARY=y # CONFIG_PREEMPT is not set && # CONFIG_HZ_100 is not set # CONFIG_HZ_250 is not set # CONFIG_HZ_300 is not set CONFIG_HZ_1000=y CONFIG_HZ=1000 CONFIG_SCHED_HRTICK=y
--- Have always leaned toward 1kHz, it divides a bunch of ways. I went with the voluntary preempt, thought max latency in no preempt might make some things shudder, while my linux box really is more akin to a server and thought voluntary preemption might be sufficient. Haven't ever noticed downsides.
Ya know, Opensuse does ship their src packages for kernels, you could always build a kernel from one of those. I like the idea of knowing what's in my kernel. I have a script to pull down latest patches from kernel.org for latest stable and I build from those patches/deltas Saves about 80% in disk space with the # kernel sources I keep around. I'd have to say building a kernel is one of the easier jobs you could try. Once you've got a build for your machine, you could even go for booting directly from disk...but takes a bit of bravery. But still if you use a currently running kernel as base sample of what drivers need to be included, its not that difficult to do.
Thomas
On 6/7/21 3:00 PM, Takashi Iwai wrote:
Well, if HZ=1000 really helps, it implies that it's no requirement of the hard RT, and kernel-preempt flavor would work enough for that purpose.
AFAIK, kernel-preempt is available for Leap. And for TW, we're going to switch to the dynamic preempt, i.e. the preemption model is chosen via boot option.
Takashi